• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10b
• /
• pp.255-256
• /
• 2003

열가소성 폴리우레탄 공중합체는 가역적 변형을 갖는 soft segment와 물리적 가교역할을 하는 hard segment로 이루어져 있으며, 이들 두 segment domain의 상분리에 의하여 우수한 탄성효과를 발휘할 수 있으며 또한 적당한 구조제어에 의하여 형상기억효과를 나타내게 할 수 있다. 본 연구자들은 최근 형상기억 폴리우레탄 제조에 있어 soft segment의 배열을 달리함으로써 보다 우수한 역학적 성질을 갖는 시료를 얻을 수 있음을 보고하였다. (중략)

• Science of Emotion and Sensibility
• /
• v.19 no.3
• /
• pp.43-50
• /
• 2016

The uniform nanofibers of polyurethane with different contents of Juniperus Chinensis extracts were successfully prepared by electrospinning method. Polyurethane is widely used as functional polymers in the industrials, medical field as their properties can be tailor-made by adjusting their compositions. Juniperus Chinensis has been reported for anti-tumor, anti-bacterial, anti-fungal, and anti-viral activities. PU/Juniperus Chinensis extracts composite nanofibers were produced at different Juniperus Chinensis extracts concentrations (0.25, 0.5, 1, 1.5wt.%). The effects of the major parameters in electrospinning process such as tip to collector distance (TCD), voltage, polymer concentration on the average diameter of electrospun nanoweb were investigated. As results, 12wt% PU solution concentration, 8kV applied voltage and 15cm tip to collector distance were identified as optimum conditions for electrospinning the composite nanofibers. The diameter and morphology of the nanocomposite nanofibers were confirmed by a scanning electron microscopy (SEM). The resulting fibers exhibited a uniform diameter ranging from 435nm~547nm. It has been found that the average diameters of fibers decreased by the adding of Juniperus Chinensis extracts. These nanowebs can be used for medical materials, protective clothing, and antimicrobial filters.

• Polymer(Korea)
• /
• v.35 no.6
• /
• pp.553-557
• /
• 2011

Poly(vinyl alcohol) (PVA)/waterborne polyurethane (WBPU)/montmorillonite clay (MMT) nanocomposite nanofibers were prepared using electrospinning technique of aqueous solutions. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and thermal gravimetric analyzer were used to characterize the morphology and properties of the nanocomposite nanofibers. Since PVA, WBPU and MMT are hydrophilic, non-toxic and biocompatible materials, these nanocomposite nanofibers can be used for filter and medical industries as wound dressing materials, antimicrobial filters, etc.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.04a
• /
• pp.384-385
• /
• 2003

최근 나노기술에 대한 관심이 급격히 부각되어짐에 따라 섬유에 있어서도 나노섬유 제조에 관하여 많은 관심이 모아지고 있다. 현재까지 알려진 나노섬유 제조법 중 공정, 설비 및 제조원가면에서 가장 유리한 전기방사법에 관하여 지대한 관심이 모아지고 있다. 전기방사법이란 고분자 용액이나 용융된 고분자에 고전압의 전하를 걸어주어 부직포를 집속 할 수 있는 금속소재의 콜렉터(collector)와 팁사이에 전기장을 형성시켜 부직포를 제조하는 방법이다 [1-3]. (중략)

• Fire Science and Engineering
• /
• v.30 no.6
• /
• pp.9-13
• /
• 2016

Anti-oxidation and flame resistant polyurethane nanofibers were prepared by electrospinning and aluminum hydroxide addition. Electrospinning was carried out under the following procedure conditions; applied voltage, 20 kV; polymer solution feeding rate, 1.2 ml/h; collector rolling speed, 120 rpm; and tip to collector distance, 15 cm. Aluminum hydroxide was added to the prepared polymer solution for electrospinning to enhance the oxidation and flame resistant properties. The thermal properties were investigated by thermogravimetric analysis to determine the polymer decomposition temperature, integral procedure decomposition temperature, final decomposition temperature, and remaining amount after thermal decomposition. The activated energy for polymer degradation was also investigated using the Horowitz-Metzger equation. The activation energy increased to more than 50%. The thermal properties of the polyurethane nanofibers were improved by a hydration reaction during the thermal decomposition of aluminum hydroxide around $300{\sim}500^{\circ}C$.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10b
• /
• pp.201-202
• /
• 2003

탄소나노튜브는 역학적 물성이 뛰어날 뿐만 아니라 전기적 특성도 우수하여 현재 매우 많은 연구와 응용개발이 시도되고 있다 일반적으로 전기전도성 고분자 복합체를 얻기 위한 방법으로 카본블랙이나 전도성 섬유, 금속섬유, 전도성 분말 등을 고분자에 혼입하는 방법을 주로 이용하지만, 복합체 내에서 나노구조 형성이 가능한 탄소나노튜브를 이용하면 나노물질의 특성상 매우 유리한 점이 많다. 예를 들면, 우수한 전기특성, 낮은 임계농도, 우수한 역학적 성질 둥이다. (중략)

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.04a
• /
• pp.376-377
• /
• 2003

전기방사(electrospinning)는 최근 나노기술의 대두와 함께 서브마이크론(submicron)의 직경을 가지는 섬유를 제조할 수 있는 방법으로 활발한 연구가 진행되고 있는 실정이다[1]. 이러한 전기방사는 고분자 용액이나 용융된 고분자에 고전압을 걸어주어, 모세관 팁과 웹을 받아주는 컬렉터(collector) 사이에 전기장을 형성시켜 섬유를 제조하는 방법이다. 열가소성 폴리우레탄은 우수한 탄성을 갖는 유용한 고분자중의 하나로 섬유나 플라스틱에 널리 사용되고 있다. 특히, 이는 고무에 비하여 탄성률이 높고 내마모성이 강하며 용매에 대한 저항성이 좋은 장점을 지니고 있다[2]. (중략)

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.6
• /
• pp.700-707
• /
• 2014

The effect of steam and ozone pretreatments on fibrillation efficiency by wet disk-milling was investigated. Hemicellulose (40%) and lignin (42%) of Korean white pine were partially removed by steam and ozone pretreatments, respectively. With increasing wet disk-milling time, the diameter of fibers was significantly decreased and its size distribution became narrow. Especially, the average diameters of lignocellulose nanofibers after steam and ozone pretreatments were 19 nm and 12 nm, respectively. Thus-obtained lignocellulose nanofibers-reinforced polyurethane composite was prepared. Tensile strength and elastic modulus were drastically improved with increasing wet disk-milling time and lignocellulose nanofiber content. Nanocomposite reinforced by lignocellulose nanofibers after two pretreatments showed higher tensile properties, compared to that reinforced by lignocellulose nanofiber without pretreatment, at the similar wet disk-milling time.

• Proceedings of the Korean Fiber Society Conference
• /
• 2007.11a
• /
• pp.263-264
• /
• 2007

See Full Text

• Proceedings of the Korean Fiber Society Conference
• /
• 2007.11a
• /
• pp.281-282
• /
• 2007